id=0
sda=7
scl=6
RC522={}
i2c.setup(0,sda,scl,i2c.SLOW)
function RC522.read(len)
    len = len or 50
    i2c.start(0)
    i2c.address(0,0x2A,i2c.RECEIVER)
    local c = i2c.read(0,50)
    i2c.stop(0)
    return string.byte(c)
end
function RC522.write()
    
end